&CELL: FIELD-MAP: format


PARAMETER-EXTRACTOR-2D

  Specifies that the field map has been generated by the Ansoft
  program called "Maxwell 2D Parameter Extractor". The format of
  these files is identified automatically, and the format doesn't
  have to be specified therefore.

  To generate your field maps with Maxwell Parameter Extractor 2D,
  you may wish to follow this recipe:

  1. Go through the various steps until "Solve Parameters", taking
     care (before drawing anything) to adjust in "Draw Cross Section"
     the "Model Drawing Size" such that it fits exactly the area of
     your detector - do not leave any empty space around it. Then
     enter "View Fields" from where you perform the following steps:
  2. Click on "calc", select "plane", if the upper area is not
     empty then click on "clear". Do also a "smooth" and a "push"
     to ensure the mesh is the same for all maps. Then click on
     "voltage" and do an ASCII "write" to a file ("write" is in
     the second set of commands to which you access via "next",
     to get back to the first set click on "prev"). Maxwell appends
     the string ".arg" to the file name you enter. This creates
     a map of the potential.
  3. Repeat step 2 with "E_vector" instead of "voltage", choose a
     file name different from the one used in step 2. This creates
     a file that contains both Ex and Ey.
  4. Click again on "calc", select again "plane", do a "clear" if
     needed. Click on "E_vector", then on "vec_cons", fill in 1 0 0
     as vector, click on "execute", click on "Materials", click on
     "epsilon", ensure that multiplication is set to "yes" and
     "execute", then click on "scalar_x" and do an ASCII "write" of
     the result. Choose a file name different from those used in
     steps 2 and 3. This procedure leads to a file that contains the
     dielectric constant.
  5. Go back to the "Parameter Extractor" main menu, click on
     "Setup Boundaries/Sources", and select "Define", confirm that
     you wish to "Modify" and then adjust the voltages of all
     electrodes such that the electrode that you wish to read out is
     at 1 V and all other electrodes at 0 V. Then "Exit", confirming
     that you wish to save the modifications.
  6. Go to the "Setup Solution Parameters" in the Parameter Extractor,
     click on "Capacitance", select "Current" as Starting Mesh, suppress
     "Adaptive Analysis". This ensures that the field is calculated on
     the same mesh as the field calculated in point 1.
  7. Write out the electric field as described in step 2, choosing
     a file name different from the names chosen in steps 2, 3 and 4.
     This generates the weighting field.

  These steps should lead to 4 files with names that end on .arg and
  that are located in the es.pjt subdirectory of your project.

  Be sure to create the E, V, epsilon and weighting field maps with
  identical meshes and the E, V and epsilon maps with identical
  boundary conditions.

  The names of these 4 files should be placed after the FILES keyword
  of the FIELD-MAP command, the name of the weighting field map should
  be preceded by the keyword "WEIGHTING-FIELD" to distinguish it from
  the regular electric field map. The order is not important. There is
  no need to specify that the files come from Maxwell Parameter Extractor
  2D.

  Information about using Maxwell at CERN can be found at
  the URL: http://wwwcae.cern.ch/Maxwell/Maxwell.html

  (Instructions from Pawel Majewski, Pawel.Majewski@cern.ch)

PARAMETER-EXTRACTOR-3D

  Specifies that the field map has been generated by the Ansoft
  program called "Maxwell 3D Parameter Extractor", version 1.1
  (Feb 1993). The format of these files is identified automatically,
  and the format doesn't have to be specified therefore.

  When generating your field maps with this program, you may wish
  to follow this recipe:

  1. Go through the various steps until "Solve Parameters", taking
     care (before drawing anything) to adjust in "Draw Cross Section"
     the "Model Drawing Size" such that it fits exactly the area of
     your detector - do not leave any empty space around it. Then
     enter "View Fields" from where you perform the following steps:
  2. Click on "calc", select "space", if the upper area is not
     empty then click on "clear". Click on "phi", do a "push" to
     ensure the mesh is the same for all maps and then "smooth" the
     potential map. Do an ASCII "write" to a file. Maxwell appends
     the string ".arg" to the file name you enter, it is therefore
     sufficient to enter for instance just "V". This creates a map
     of the potential.
  3. Repeat step 2. for "E_vector" and "D_vector", without doing a
     "push", and writing to files with different names. Creating
     the D field map is optional.
  4. You may also wish to create a weighting field map as described
     for Maxwell Parameter Extractor 2D.

  This procedure should create maps of the electrostatic potential,
  the E field, the D field and perhaps of a weighting field. The
  dielectric constants are computed by comparing E and D. These files
  will be located in the efs3d.pjt subdirectory of your project.

  Be sure to create the E, V, D and weighting field maps with
  identical meshes and the E, V and D maps with identical boundary
  conditions.

  Information about using Maxwell at CERN can be found at
  the URL: http://wwwcae.cern.ch/Maxwell/Maxwell.html

FIELD-SIMULATOR-3D

  Specifies that the field map has been generated by the Ansoft
  program called "Maxwell 3D Field Simulator", version 4.0.
  The format of these files is identified automatically,
  and the format doesn't have to be specified therefore.

  When you use this program to create your field maps, you have
  to provide the following to Garfield:

  1. The mesh: The mesh is contained in a .hyd and a .pnt file
     stored in the project directory (and not in an "efs3d.pjt"
     subdirectory of the project directory). The files have names
     like "fileset2", "fileset1", "current", "efs3d", "previous"
     and "initial".

     - If you do not specify a mesh file yourself, then Garfield
       will look, in the directory of the first field map, for
       mesh files with the above names, starting from "fileset2".

     - To select a mesh manually, you provide the name of either
       the .hyd or the .pnt file (complete file name) and either
       place this name first in the list of files to be read, or
       identify it explicitely as containing a mesh by prefixing
       the MESH keyword.

  2. The field maps of V, D and E written out in .reg format. With
     Maxwell 3D Field Simulator, there is no need to smooth the
     field maps, as opposed to Maxwell 3D Parameter Extractor.

     The field maps can be created as follows: After having gone
     through the various steps, in the "Post Process" menu, select
     "Nominal Problem". From the "Data" menu, select "Calculator".
     In the "Input" column select the "Qty" menu where you pick
     "phi". In the "Output" column select "Write ..." and write out
     the field to a file called, for instance, "V.reg". Repeat the
     same steps replacing "phi" by "E" and "D".

  3. Optionally, you may also provide a weighting field. The
     weighting field is the electric field that is obtained by
     setting the potential of all conductors to 0 V except the
     read-out conductor which is set to 1 V.

  Be sure to create the E, V, D and weighting field maps with
  identical meshes and the E, V and D maps with identical boundary
  conditions.

  Information about using Maxwell at CERN can be found at
  the URL: http://wwwcae.cern.ch/Maxwell/Maxwell.html

Keyword index. Formatted on 10/11/98.